Acquisitions and Divestitures (Divestitures Narrative) (Details) $ in Millions									3 Months Ended				9 Months Ended
	Sep. 03, 2016 USD ($) item	Feb. 01, 2016 USD ($) item	Jan. 01, 2016 USD ($) item	Jul. 31, 2015 USD ($) item	Apr. 01, 2015 USD ($) item	Mar. 01, 2015 USD ($) item	Feb. 01, 2015 USD ($) item	Dec. 31, 2014 USD ($)	Sep. 30, 2016 USD ($) item	Jun. 30, 2016 USD ($)	Mar. 31, 2016 USD ($)	Jun. 30, 2015 USD ($) item	Sep. 30, 2016 USD ($) item	Sep. 30, 2015 USD ($)	Sep. 29, 2016 item	Jan. 01, 2015 item
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of Hospitals Sold | item													7
Proceeds from Divestiture of Businesses, Net of Cash Divested | $													$ 12	$ 87
Impairment of goodwill | $										$ 1,395			1,395
Impairment of goodwill and long-lived assets | $									$ 39				1,695	$ 6
Goodwill, Written off Related to Disposal of Assets Held-for-Sale | $													$ 31
Hospitals Included in Held for Sale Member
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Goodwill, Written off Related to Disposal of Assets Held-for-Sale | $									$ 31
Riverview Regional Medical Center [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal Date													Mar. 01, 2015
Number of licensed beds | item						281
Proceeds from Divestiture of Businesses, Net of Cash Divested | $						$ 25
Carolina Pines Regional Medical Center [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal Date													Jan. 01, 2015
Number of licensed beds | item																116
Proceeds from Divestiture of Businesses, Net of Cash Divested | $								$ 74
Williamson Memorial Hospital [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of licensed beds | item									76				76
Harris Hospital [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal Date													Feb. 01, 2015
Number of licensed beds | item							133
Proceeds from Divestiture of Businesses, Net of Cash Divested | $							$ 5
Dallas Regional Medical Center [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal Date													Mar. 01, 2015
Number of licensed beds | item						202
Proceeds from Divestiture of Businesses, Net of Cash Divested | $						$ 25
Chesterfield General Hospital [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of licensed beds | item					59
Chesterfield General Hospital and Marlboro Park Hospital [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal Date													Apr. 01, 2015
Proceeds from Divestiture of Businesses, Net of Cash Divested | $					$ 4
Marlboro Park Hospital [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of licensed beds | item					102
Fallbrook Hospital [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of licensed beds | item												47
Proceeds from Divestiture of Businesses, Net of Cash Divested | $												$ 3
Payson Regional Hospital [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal Date													Jul. 31, 2015
Number of licensed beds | item				44
Proceeds from Divestiture of Businesses, Net of Cash Divested | $				$ 20
Lehigh Regional Medical Center [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal Date													Feb. 01, 2016
Number of licensed beds | item		88
Proceeds from Divestiture of Businesses, Net of Cash Divested | $		$ 11
Impairment of goodwill and long-lived assets | $											$ 4
Bartow Regional Medical Center [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal Date													Jan. 01, 2016
Number of licensed beds | item			72
Proceeds from Divestiture of Businesses, Net of Cash Divested | $			$ 60
Impairment of goodwill and long-lived assets | $											5
McNairy Regional Hospital [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Impairment of goodwill and long-lived assets | $											$ 7
Alliance Health Blackwell [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal Date													Sep. 03, 2016
Number of licensed beds | item	53
Impairment of goodwill and long-lived assets | $	$ 3
Curae Health, Inc. [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal Date													Sep. 29, 2016
Number of hospitals classified as held for sale | item															4
Merit Health Gilmore Memorial [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of licensed beds | item															95
Merit Health Batesville [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of licensed beds | item															112
Merit Health Northwest Mississippi [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of licensed beds | item															181
Highlands Regional Medical Center [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of licensed beds | item															126